Liquid crystal display devices driven by a transverse electric field have been drawing attention due to satisfactory viewing characteristics, for example, of an in-plane switching (IPS) mode and a fringe field switching (FFS) mode. An IPS liquid crystal display has a better view angle than a twisted nematic (TN) or vertical alignment (VA) liquid crystal display device, as is disclosed in Japanese Patent Application Laid-Open No. 2002-55341. Such an advantage is probably caused by a parallel alignment of liquid crystal molecules to the face of a liquid crystal cell substrate in an IPS or FFS liquid crystal cell. As is disclosed in Japanese Patent Application Laid-Open Nos. 2002-55341 and 2004-94219, however, liquid crystal molecules in an IPS liquid crystal cell are not perfectly parallel to the face of a liquid crystal cell substrate. In particular, the longitudinal axes of the liquid crystal molecules are aligned with a tilt angle to the substrate face in the thickness direction, near the face of the substrate. This tilt angle of the aligned liquid crystal molecules affects the viewing characteristics.
A birefringence film disclosed in Japanese Patent Application Laid-Open No. 2002-55341 is disposed between a liquid crystal cell substrate and a polarizing plate and has optical anisotropy of a sign opposite to that of the liquid crystal molecules. The birefringence film has an optical axis that tilts at the same angle in the same direction as the liquid crystal Molecules in the liquid crystal cell. This reduces light leak in an oblique direction. A positive birefringence material disclosed in Japanese Patent Application Laid-Open No. 2004-94219 reduces the light leak in an oblique direction.